Fluorine-18 fluorodeoxyglucose uptake in the retractile testis

A 51-year-old man with a palpable mass in his right inguinal region had flu orine-18 fluorodeoxygluclose (F-18 FDG) whole-body positron emission tomogr aphy (PET) in our cancer screening program. FDG accumulated in the mass, su ggesting a metabolically active lesion that was likely malignant. A pelvic MRI and a urologist's palpation revealed that his inguinal mass was a retra ctile testis. Because a retractile testis is a benign process with no need for interventional therapy, it would be considered a false-positive finding on the cancer screening program using F-18 FDG PET.